[RueyTeh]

Hi everyone, i need to plot a( flow increase curve)graph of inlet and outlet volume flow ratw versus time, but i not sure the method i use are correct or not. I create a surface monitor of inlet and outlet volume flow rate but i get weird result, for example the inlet is 2 the outlet are -2 .
The target Of result are looks like the picture below:


Anyone can help me ASAP?

[KaLium]

Originally Posted by RueyTeh

I create a surface monitor of inlet and outlet volume flow rate but i get weird result, for example the inlet is 2 the outlet are -2 .

That is normal in fluent monitors. Outlet flows are negative.

[RueyTeh]

Originally Posted by KaLium

That is normal in fluent monitors. Outlet flows are negative.

My target of data is outlet volume flow rate must multiply the intake air by 15 times. What is mean by the negative outlet flow rate?
The integral velocity magnitude in fluent also have unit m3/s , is it represent volume flow rate too?

[LuckyTran]

Originally Posted by RueyTeh

My target of data is outlet volume flow rate must multiply the intake air by 15 times. What is mean by the negative outlet flow rate?
The integral velocity magnitude in fluent also have unit m3/s , is it represent volume flow rate too?

Negative volume flow means the flow is going outward. Positive would be inward.

Integral of velocity over a surface should have units of m^3/s because it has units of velocity times units of area.

The integral of velocity magnitude over a surface is not the volume flow rate. A quick counter-example is I have infinite velocity parallel to a surface, the integrated volume magnitude would be infinite but there would be no flow across the surface.

The integral of the normal component of velocity with respect to the surface over the area is the volumetric flowrate, by definition.

[RueyTeh]

Originally Posted by LuckyTran

Negative volume flow means the flow is going outward. Positive would be inward.

Integral of velocity over a surface should have units of m^3/s because it has units of velocity times units of area.

The integral of velocity magnitude over a surface is not the volume flow rate. A quick counter-example is I have infinite velocity parallel to a surface, the integrated volume magnitude would be infinite but there would be no flow across the surface.

The integral of the normal component of velocity with respect to the surface over the area is the volumetric flowrate, by definition.

Sorry to have so many question. I have single data of inlet and outlet volume flow rate in one simulation only, how can i have multiple inlet and outlet volume flow rate data that shows on the picture with one simualtion only ? If i tick the target mass flow rate, can i obtain the desire result?

[LuckyTran]

You need to run more than one simulation and record the inlet and outlet volume flow rate. Then you make the plot in excel for example.